Severe hepatotoxicity caused by the tropical cyanobacterium (blue-green alga) Cylindrospermopsis raciborskii (Woloszynska) Seenaya and Subba Raju isolated from a domestic water supply reservoir

Cylindrospermopsis raciborskii, a tropical blooming species of cyanobacterium (blue-green alga), was isolated from the domestic water supply reservoir on Palm Island, a continental island off the tropical northeast coast of Australia. This species, not previously known to be toxic, was shown to be severely hepatotoxic for mice. The 50% lethal dose at 24 h after injection was found to be 64 +/- 5 mg of freeze-dried culture per kg of mouse. The principal lesion produced was centrilobular to massive hepatocyte necrosis, but various degrees of injury were also seen in the kidneys, adrenal glands, lungs, and intestine. The possible implication of this finding in relation to an incident of hepatoenteritis in humans living on the island is discussed.     

Analysis of factors that influence energy expenditure in honeyeaters (Meliphagidae)

The energy expenditure of the tūī (Prosthemadera novaeseelandiae), a meliphagid endemic to New Zealand, was measured and compared with 20 species of honeyeaters (family Meliphagidae) to determine whether its expenditure is influenced either by life in a moist, temperate climate or an island residence. Body mass in the honeyeaters accounted for 91.5% of the variation in basal rate. The combination of body mass, climate and the maximal limit to an altitudinal distribution explained 98.6% of the variation in basal rate with tropical, low-altitude species having the highest mass-independent rate. The basal rates of meliphagids in tropical highlands are similar to those in temperate lowlands, which may reflect similar food supplies. The tūī mass-independent expenditure appears to reflect an active lifestyle in a temperate climate with no evidence that an island residence influenced its rate, whereas sedentary birds on New Zealand have responded to island life with a depressed basal rate. An effective analysis of the variation in energy expenditure requires the inclusion of the ecological and behavioural characteristics that distinguish species.     

Biogeography of milkweed butterflies (Nymphalidae: Danainae) and mimetic patterns on tropical Paciflc archipelagos

Distributions of danaine butterfly species and associated mimetic patterns were compared among fifteen archipelagos of the tropical Pacific Ocean, and within five major archipelagos (the Bismarcks, Fiji, East and West Solomon Islands, and Vanuatu). Using both simple and stepwise linear regression analysis, variation in the total number of danaine species and number of mimetic patterns was assessed with respect to island size, isolation and elevation. Relative to interarchipelago distributions, the distribution of danaine species and number of mimetic patterns on islands within archipelagos exhibited less dependence upon interisland distance and island area. Geographical features influencing the number of mimetic patterns were similar to those of danaines as a whole. Analysis of residuals from stepwise linear regression suggested that factors influencing danaine distributions were different from those for non-danaine butterflies. This result is consistent with the hypothesis of enhancement of danaine species establishment through Müllerian mimicry, although other factors such as host plant availability and similar habitat use may also be important.     

Assessing habitat suitability for the translocation of Ochrosia tahitensis (Apocynaceae), a critically endangered endemic plant from the island of Tahiti (South Pacific)

Reintroduction or translocation of threatened plant species, as part of in situ conservation efforts, often failed because of the lack or the poor quality of remaining natural habitats due to human disturbances and invasion by alien species, especially in island ecosystems. We conducted a study on Ochrosia tahitensis (Apocynaceae), a critically endangered endemic small tree in the tropical high volcanic island of Tahiti (French Polynesia, South Pacific) to find the most suitable sites for future translocation. Distribution models were produced based on climate, topography, and plant community inventories (i.e. species composition and abundance, canopy height and openness, basal area of woody species) of the few remnant populations. Results show that this species, comprising 32 reproductive trees within 16 populations known in the wild, remains restricted to a few ecological refuges representing a very small part of its potential ecological range located on the northwest side of the island, and shares its current habitats with a set of more common native woody species found in mesic-wet forests. The use of native plant communities as a proxy for habitat suitability along with species distribution modelling can enhance translocation success in island ecosystems, but only if the major threats causing population decrease, mainly forest destruction and fragmentation and invasive alien species, are effectively managed.     

Invasive Temperate Species are a Threat to Tropical Island Biodiversity

To protect the remaining biodiversity on tropical islands it is important to predict the elevational ranges of non-native species. We evaluated two hypotheses by examining land snail faunas on the eastern (windward) side of the island of Hawaii: (1) the latitude of a species' native region can be used to predict its potential elevational range and (2) non-native temperate species, which experience greater climatic fluctuations in their native range, are more likely to become established at higher elevations and to extend over larger elevational ranges than non-native tropical species. All non-native tropical species were distributed patchily among sites ≤500 m and occupied small elevational ranges, whereas species introduced from temperate regions occupied wide elevational ranges and formed a distinct fauna spanning elevations 500–2000 m. Most native land snail species and ecosystems occur >500 m in areas dominated by temperate non-native snail and slug species. Therefore, knowing the native latitudinal region of a non-native species is important for conservation of tropical island ecosystems because it can be translated into potential elevational range if those species are introduced. Because temperate species will survive in tropical locales particularly at high elevation, on many tropical islands the last refuges of the native species, preventing introduction of temperate species should be a conservation priority.     

Species delimitation in the Chinese bamboo partridge Bambusicola thoracica (Phasianidae; Aves)

Although tropical and subtropical Asia harbour a high level of species diversity, their species richness can be underestimated because species which are in fact distinct have not been separately identified. In this study, we delimit Bambusicola thoracica into two full species, the Chinese bamboo partridge (B. thoracica) in continental Asia and the Taiwanese bamboo partridge (B. sonorivox) on the island of Taiwan, using coalescent‐based multilocus division and diagnosable vocalization patterns. Isolation‐with‐migration analysis indicated that the two bamboo partridges diverged approximately 1.8 million years ago, with gene flow present most probably during the early stages of their divergence. This conclusion supports the hypothesis that diverging lowland lineages spread across the Asian mainland, and continental islands have more opportunities for secondary contact than highland ones when the sea level was low. Our results imply that conservation of biodiversity in tropical and subtropical Asia could be hindered by overlooking numerous ‘hidden’ species and highlight the importance of re‐examining the taxonomic statuses of species in this region traditionally defined as polytypic.     

The bark and ambrosia beetles (Curculionidae, Scolytinae) of Cocos Island, Costa Rica and the role of mating systems in island zoogeography

Cocos Island is a small oceanic island midway between Costa Rica and the Galápagos Archipelago; about 2 Myr in age, it is the only tropical oceanic island in the eastern Pacific with tropical wet forest. We identified several hundred bark beetle specimens collected during recent expeditions by INBio, the National Biodiversity Institute of Costa Rica, and re-examined all specimens from earlier collections. We report 19 species in ten genera, seven or eight of which are endemic, making scolytines the largest group of beetles known from the island. We describe as new Pycnarthrum pseudoinsulare , Xyleborinus cocoensis , and Xyleborus sparsegranulosus , resurrect Xyleborus bispinatus as separate from X. ferrugineus , and report six other species as new to Cocos Island. Three-quarters of the scolytines reproduce by brother–sister mating, and we argue that inbreeders are superior island colonists because they are less affected than are outbreeders by problems of mate location and inbreeding depression. The fauna and flora of Cocos Island arrived by dispersal and human transport. We examine natural colonization patterns for the fauna, using the distributions of the relatives of island endemics: most colonization came from the Americas, but the closest relatives to some endemics are found on Caribbean or Galápagos islands. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 729–743.     

Two new Marina (Leguminosae) from the southern Baja California peninsula, Mexico

Marina victoriae andM. brevis are newly described species from the southern Baja California peninsula, Mexico. The former is a perennial herb locally abundant in the eroded hillsides at the foothills of Sierra de la Victoria, where an oak woodland and a dry tropical forest meet. The latter is an elusive ephemeral inhabiting a narrow strip of land between the mangroves and the desert scrub on an island in the Gulf of California. These two new species belong to the seriesChrysorrhizae, a group native to the Gulf of California basin.     

The ‘Island Rule’ Acting on Anuran Populations (Bufonidae: Rhinella ornata) of the Southern Hemisphere

Darwin and Wallace, in the mid‐nineteenth century, were the first to document examples of natural selection acting on island dwellers. A century later a pattern of morphological differences among organisms on islands was coined the ‘island rule’, which states that on islands species with small individuals tend toward gigantism and large individuals tend toward dwarfism. Selective pressures such as limited resources and increased intraspecific competition modulate the size of organisms in these environments. Of the several works that have tested vertebrates for adherence to the island rule only two have addressed amphibians. This work is the third record of body size variation of island amphibian populations, and the first for the Southern Hemisphere. The islands investigated were once continuous with mainland, and now are isolated as a result of sea level fluctuations that took place in the Pleistocene and Holocene. This study compared morphometric variation in populations of Rhinella ornata (Bufonidae) occurring on three islands of the Costa Verde to populations on five continental areas in Rio de Janeiro, Brazil. We measured 18 morphometric variables of 177 individuals. There was a shift toward smaller body size (dwarfism) in two of the three island populations studied. We attribute this general pattern to geographic factors, verifying the expression of the island rule in tropical frogs populations (insular dwarfism) operating inversely in relation to those of temperate environments (island gigantism).     

Signals of recent spatial expansions in the grey mouse lemur (<Emphasis Type="Italic">Microcebus murinus</Emphasis>)

Background  

Pleistocene events have shaped the phylogeography of many taxa worldwide. Their genetic signatures in tropical species have been much less explored than in those living in temperate regions. We analysed the genetic structure of a Malagasy primate species, a mouse lemur with a wide distribution (M. murinus), in order to investigate such phylogeographic processes on a large tropical island. We also evaluated the effects of anthropogenic pressures (fragmentation/deforestation) and natural features (geographic distance, rivers) on genetic structure in order to complement our understanding of past and present processes of genetic differentiation.     

168 Cell Wall Proteomics of the Green Alga Haematococcus Pluvialis (Chlorophyceae)

Coral reefs of US-held islands in the central Pacific Ocean are among the most pristine in the world and represent over 93% of the reef systems under United States jurisdiction. The remote location of many islands has limited past algal research, resulting in incomplete understanding of species diversity, quantity, and ecology. Starting in 2000, the Coral Reef Ecosystem Investigation (CREI) began rapid ecological assessments on many Pacific island reefs to monitor ecological changes in reef biota over time. During the past year, algal efforts have concentrated on the French Frigate Shoals (Northwestern Hawaiian Islands) where we have increased the number of algal species reported by 1000%. Additionally, species new to science, including Acrosymphyton brainardii and Scinaia huismanii, have been described. Quantitative field sampling using a photoquadrat method is revealing species of the green algae Halimeda and Microdicyton to be ecological dominants in many areas during late summer/early autumn. Preliminary analyses with Primer software show species composition and abundance of all benthic organisms to differ significantly between most field sites sampled. Additional benthic habitat mapping of Pacific island reefs by CREI researchers is breaking the long-held paradigm that macroalgal cover is minimal in healthy tropical reef systems. Videotape analyses of benthic communities often find over 50% algal cover from 1 to 20 meter depths in many locations. Common ratios of macroalgae, turf algae, and crustose coralline algae to corals, other benthic organisms and substrate types on US Pacific reefs are being calculated for the first time.     

基于叶片解剖性状探究29种植物对热带珊瑚岛的适应策略

为探究植物对热带珊瑚岛高温、强光照、干旱、盐碱等极端环境的适应策略，分别以生长于海南文昌苗圃和移栽至热带珊瑚岛的29种植物为研究对象，对其叶片性状进行测定和比较分析。结果表明，与海南文昌的同种植物相比，热带珊瑚岛的草本植物除干物质含量增加外其他性状均无显著改变；而木本植物的比叶面积显著下降，叶片厚度和叶片干物质含量显著增加，海绵组织更厚且栅栏组织排列更紧密，但气孔长度、气孔密度及气孔面积指数无显著差异。岛上木本植株采取慢速投资-收益的资源获取策略，将更多的资源投入到叶片构建中从而增强逆境下的适应性，并且通过非气孔调节的方式提高光合与储水的潜力以抵御胁迫。栽植于热带珊瑚岛的29种植物能够采用更保守的资源利用策略，较好地适应干旱、强光照等胁迫环境，可用于热带珊瑚岛植被构建。     

Migration, isolation and hybridization in island crop populations: the case of Madagascar rice

Understanding how crop species spread and are introduced to new areas provides insights into the nature of species range expansions. The domesticated species Oryza sativa or Asian rice is one of the key domesticated crop species in the world. The island of Madagascar off the coast of East Africa was one of the last major Old World areas of introduction of rice after the domestication of this crop species and before extensive historical global trade in this crop. Asian rice was introduced in Madagascar from India, the Malay Peninsula and Indonesia approximately 800-1400 years ago. Studies of domestication traits characteristic of the two independently domesticated Asian rice subspecies, indica and tropical japonica, suggest two major waves of migrations into Madagascar. A population genetic analysis of rice in Madagascar using sequence data from 53 gene fragments provided insights into the dynamics of island founder events during the expansion of a crop species' geographic range and introduction to novel agro-ecological environments. We observed a significant decrease in genetic diversity in rice from Madagascar when compared to those in Asia, likely the result of a bottleneck on the island. We also found a high frequency of a unique indica type in Madagascar that shows clear population differentiation from most of the sampled Asian landraces, as well as differential exchange of alleles between Asia and Madagascar populations of the tropical japonica subspecies. Finally, despite partial reproductive isolation between japonica and indica, there was evidence of indica/japonica recombination resulting from their hybridization on the island.     

Establishment of a free-ranging colony of Stumptail macaques (Macaca arctoides): Relations to the ecology I

A group of 20 Stumptail macaques was released free on the island of Totogochillo in lake Catemaco, Veracruz, Mexico, on August 15 of 1974. Initial adaptations to the island geography and ecology are reported for the first 83 days of observation. The island of Totogochillo is a lava formed island with vegetation type consisting of secondary tropical rain forest. The Stumptail group composition consisted of one adult male, five adult female and 14 non adult individuals. Individuals and matrilineal genealogies are identifiable. Home range is limited by the island's size. The macaques only have one sleeping site. The use of resting areas seems to be related to variations in the travelling and foraging patterns of the Stumptails. Five travelling routes have been identified and changes in these are associated to changes in the availability and distribution of natural edibles. Feeding adaptations consitst of consumption of vegetal matter such as leaves, seeds, roots, flowers, and tree bark. Of 65 major plant species identified the Stumptails consume 28% (N: 18). Sex differences in foods eaten were not observed but age differences do exist. The macaques prey on crickets, spiders, birds, and water snails. A food pressures is suggested to induce the monkeys to locate new food resources. Predators on the island are not existent but avian predators are present in the area. The Stumptails respond to their presence with alarm calls and an attack by a hawk on the group was witnessed. Sentinele behaviour was performed by an adult female while protecting and scouting were carried out by the adult male in the group. During the course of the study four deaths occurred, two infants were born and on November 7th, 12 more Stumptails were released on the island. Continuing research consists of studies of the ontogeny of social relations and of the sexual behaviour in the Stumptail group against a background of known social structural relations and kinship ties. This work was supported by grants from Behavioral Sciences Foundation and by NSF-No. GB42235.     

Testing for biogeographic mechanisms promoting divergence in Caribbean crickets (genus Amphiacusta)

Aim This work examines whether the history of diversification of Amphiacusta (Orthoptera, Gryllidae) in the Caribbean corresponds to a vicariant or a dispersalist model. Location The Greater Antillean islands of the Caribbean region. Methods The phylogenetic relationships among species were estimated using a procedure that directly estimates the underlying species tree from independent loci (in this case, one mitochondrial and one nuclear locus). This tree was then used to test for topological congruence with a vicariant model, and to estimate divergence times. Results The analyses based on the expected pattern of species divergence (i.e. species‐tree topology) support a vicariant model. With the notable exception of a dispersal event marking the colonization of Jamaica, the timing of the events are generally consistent with a vicariant scenario, given the current taxon sampling and potential errors with dating the divergence events. Main conclusions The tendency of species to co‐segregate by island suggests that intra‐island diversification is common. Despite their flightlessness, species of Amphiacusta are apparently capable of long‐distance dispersal, such as colonization from the Puerto Rican/Virgin Island bank to Jamaica. The topology of the species tree is consistent with a vicariant model of divergence, and the dates of divergence between island groups are generally consistent with an island–island vicariance model. A strict island–island vicariance scenario can, however, be rejected because of inferred dispersal events such as the colonization of Jamaica. Nevertheless, the biogeographic tests suggest that most of the diversity was generated under a combination of intra‐island diversification and island–island vicariance. Additional sampling of taxa will be needed to verify this hypothesized scenario. Our findings indicate that Amphiacusta presents an ideal opportunity for examining the role of sexual selection in promoting diversification, which would complement the large number of studies focused on adaptive divergence of Caribbean taxa.     

长春花(Catharanthus roseus)对热带珊瑚岛生理生态适应性研究

长春花(Catharanthus roseus)是夹竹桃科的一种亚灌木植物,具有重要的药用价值和观赏价值,在前期的试验性种植中,发现长春花对热带珊瑚岛环境有很强的适应性。为了探讨长春花对热带珊瑚岛环境的生理生态适应性,该文以移植到热带珊瑚岛的长春花和生长于海南省文昌市苗圃的长春花为研究对象,对其叶片的形态解剖结构、生理学特征、营养元素含量等进行了分析。结果表明:(1)与苗圃生长的长春花和其他耐胁迫的植物相比,移植到热带珊瑚岛上的长春花具有叶片厚、栅栏组织发达、比叶面积小等形态解剖特征,这些特征有利于其光能吸收、水分储存和对环境资源的利用。(2)长春花的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性较高,表现出较强的抗氧化性和抗胁迫能力。(3)长春花的叶绿素a和叶绿素b含量较低,可以减少过多的光能进入叶绿体光合系统,防止过剩的光能对光合系统产生伤害。(4)热带珊瑚岛土壤养分含量低,但生长在岛上的长春花叶片的营养元素含量高,表现出很强的养分吸收和利用能力。因此,长春花对干旱、贫瘠等恶劣生境具有很好的适应能力,可以作为热带珊瑚岛植被恢复工具种。     

Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae)

The endemic Hawaiian lobeliads are exceptionally species rich and exhibit striking diversity in habitat, growth form, pollination biology and seed dispersal, but their origins and pattern of diversification remain shrouded in mystery. Up to five independent colonizations have been proposed based on morphological differences among extant taxa. We present a molecular phylogeny showing that the Hawaiian lobeliads are the product of one immigration event; that they are the largest plant clade on any single oceanic island or archipelago; that their ancestor arrived roughly 13 Myr ago; and that this ancestor was most likely woody, wind-dispersed, bird-pollinated, and adapted to open habitats at mid-elevations. Invasion of closed tropical forests is associated with evolution of fleshy fruits. Limited dispersal of such fruits in wet-forest understoreys appears to have accelerated speciation and led to a series of parallel adaptive radiations in Cyanea, with most species restricted to single islands. Consistency of Cyanea diversity across all tall islands except Hawai ;i suggests that diversification of Cyanea saturates in less than 1.5 Myr. Lobeliad diversity appears to reflect a hierarchical adaptive radiation in habitat, then elevation and flower-tube length, and provides important insights into the pattern and tempo of diversification in a species-rich clade of tropical plants.     

The species of Ceramium (Ceramiaceae,Rhodophyta) around Taiwan

A taxonomic study was recently carried out on the species of Ceramium occurring around Taiwan. One hundred and fifty-one collections were made from January 1993 through spring 1994 at 75 sites distributed around the island. A total of thirteen species were found, including three for which names cannot currently be assigned: Ceramium aduncum, C. ciliatum, C. cimbricum, C. cliftonianum, C. flaccidum, C. gracillimum var. byssoideum, C. mazatlanense, C. nakamurai, C. paniculatum, C. tenerrimum and unidentified species 1, 2 and 3. Among these are three new records for Taiwan, C. cimbricum, C. cliftonianum, and C. mazatlanense. This paper summarizes the taxonomic characters of these species and presents a key for their identification. Distribution records of all 42 species reported from the tropical western Pacific are compared. This report is the first detailed record of the genus for Taiwan.     

Egg production, development and growth in Moina micrura Kurz (1874) (Cladocera: Moinidae)

Laboratory observations on the egg production, development and growth in the Cladoceran Moina micrura show that this species has a life span of 13 days during which it produces 6M 8 eggs. Two preadult and eleven adult instars were recorded at a temperature range of 28°–30°C. The rate of egg production calculated on a cumulative basis was found to be lower (a = 1.0368) than that of other tropical species. The embryonic stages in Moina micrura closely resembled other cladoceran species, although with a short development period of 24 h. The total life span, growth rate and the total number of eggs produced in Moina micrura have been compared with those of allied tropical, temperate and arctic daphnids. The significance of this relationship to secondary productivity in tropical ecosystems has been discussed.     

The past,present and future of thermophilous Cyperus polystachyos Rottb. (Cyperaceae) on the island of Ischia (southern Italy)

Cyperus polystachyos is a hygrophilous, thermophilous and heliophilous plant with a punctiform distribution in southern Italy, where it is almost exclusively found on Ischia, an island in the Bay of Naples characterized by widespread volcanic hydrothermal activity. This species is a native of tropical and subtropical areas and there is evidence for ancient isolation events in the creation of its current distribution pattern. We have studied the historical literature available for this plant since 1800 and collected temporal and spatial presence data of this species in order to develop a habitat suitability map based on a GIS approach and using a multiple linear regression model. Moreover, we have used univariate and multivariate statistical analysis. The results show the importance of the environmental mosaic around fumaroles to preserve the species; urbanization and geothermal energy use of fumaroles in the past and the combination of abandonment of the typical agricultural system and the natural occurrence of reforestation in the present are the main causes of the decline in the number of populations.